Compound rotary pump.



G. E. HULTGRBEN. GOMPOUND ROTARY PUMP.

Patented sepia. 22, 1914.

. vide a s1mple,

" To clll whom it mag concern.-

B ki1own that -I, CHARLESE. Her. n. G N, i citizenof the United States, residupon the 'similar numioer of bars 12,

mIJ STACP S PATENT OFFCE.

GALIFQBNIA.

inglat O akland,in the county of Alameda andState of California, llVe, invented new land 1isefl Impr0vementsin Compound R0- tary"P imps, of spe"eifiation.

which the following is a This"rvention relates to a rotary pump.

The purpse of this intention is te procompact, cheaply manufactur"ed puinp of the rotary type, whieh is adapted or various pi1rposes such as pnmp ing water, 0il or any liquid matter, as well as air and vacnum.

The main object of this invention is to construct a pair of revelvixig transmission rotors having large contaet surfaees pro vided with means to prevent leakage be tweenthe rotors and containing easing, and which are also previdecl with pecnliarshapeclrecesses wl1ich will consiclerably increase the capacity of the pump, an d liieh will also permit a steady flow of hqu1d as they revol"e at botl1 higlrand l0\ v speed,

thus el1m1nating pulsating 01, knocking movement generally occurring in reeiprocating pumps.

The inventionconsists of the parts and the construction and combination of parts as hereinafter more fully described and claimed, having reference to the agcompanying drawings, in which Figure 1 is a vertical centra l section. Fig. 2 is a plan view, partly in seetien.

Referring to the clraviings: A indiates a casing in which is appropriately journaled, as at 2 and 3, a pair 0 shafts 4 and 5, upo1i which is suitably secured, as at'6 and 7, a pair of transmission retors or pistons 8 and 9. One-half of each pist0n member is considerably redueed in diameter, as indicated at 10, and the pistons are so pesitioned With rlation te eacli other that the large diam; eter of one piston will contact With the smaller diameter 01 the opposite piston. For the purpose of preventing leakage between the eontacting surfaces of the pistons, as these intermesh in their rev-lution With relatien te each ether, a plurality of slots have been cut across the aces of the pistons 11. Mountecl in these slots are a and interposed catecl at betWeen the bars and the bottom of the slots,

Speeificatun of Letters Patent. Applleation fllecl July 30, 1913. Seral 110.781,993.

small diameter of same, as indi-' comromm murw. rum.

for the purpose of yieldablysupporting the bars, are a suitable number of springs 13.

Extending through the ends of each bar, as indicated at 14 and 15, is a pair of headed retaining bolts 16 and 17 theends of which are t-hreaded and secured in the pistons. The outward niovement of the bars 12 within the slots can thus be adjusted, and the bars are further prevented from being entirely projected out of the slots by the springs 13.

Mounted upon the outer end of the shafts 4 and 5 is a pair of transmission gears 4% and 5*, and a driving pulley (n0t here sl1own) -may be inounted on the Outer end of the shaft 4 for the purpose of transmit- Patented Sept. 22, 1914.

ting revolving movement through the gears 4? and 5 for the purposeef revolving the pistons 8 and 9 with relation to eaeh other.

The driving gears 4 and 5 may be suitably inclosed by a secondary casing, indicated at B, which may be partly filled with a lubricant so as to autmatically lubricate the revolving parts. The main casing A, within which the pistons 8 and 9 arerevolubly mounted, is provided With an inlet opening 18 en the lower side, and an outlet opening 19 on-the upper side.

In operation it can readily be seen that when the rotors revolve in opposite directions, as indicated by small arrovvs a and 6, suctien Wlll be produced by the larger diameters of the pistons, as these pass the '1nlet opening. by the suction into the annular spaees formeel between the smaller diameters of the pistons and the casing, asindicated at 20, and Will finally be discharged from the pump through the outlet opening in a similarmanner. Thepiston 9 is here shewn as taking water, while the larger diameter of piston 8 is discharging water, through the outlet opening 19. The yielding packing bars mounted in the opposite pistons will always form a perfectly tight joint between the rotors so as to prevent any leakage between same. The fluid eirculated by the pump will thus be adm-itted through the opening 18 and canght in the recesses between the revolving vanes, to be finally discharged at 19; the wide, outer convex faces of the pist0ns beir1g suflicient to prevent leakage around the onter surfaces of the pistons and the casing.

The pump here shown is neat in appear- The liquid will thusbe elevated.

ance, compact inc0nstruction and reliable in action, and takes less space than so-called gea'r pumps of similar capacity. The wide,-

convex surfaces formed between the pistons and the casings, together with the packing bars interposed between the contacting surfaces of the rotors as these intermesh, permit of high eflciency as Ieakage is practica1ly eliminated. F urthermore, a constant, even dscharge is always maintained as one recess filled vvith water begns its discharge at approximately the same moment that'the opposite recess is completing its discharge; an even flow is thus always maintained regardless of the speed of the pump, and pulsation or knocking movements, t0 Which reciprocating pumps a're generally subjected, are entirely eliminated.

Having. thus described my invention, What I claim and desire t0 secure by Letters Patent, is:

In a pump, a casing having an inlet and an outlet, a pair of pistons in the casng, each of said pistons having a smooth uninterrupted large peripheral portion and a substant1ally sem-circular reduced peripheral portion which forms a, single pair of abutments that are peripherally curved and have concave bases on their inner sides which mergeinto the peripheries of the reduced portions whereby the outer curved side portion of the abutment of one piston will snugly fit in the concavity at the nn side ofthe corresponding abutment on the wtnesses.

CHARLES E. HULTGREEN.

Witnesses C. W. GANDY, P. A. BRISCOE.

five cents each, by addressing the Co1nmissoner of Iate11ts,

W uhington, D. 0." 

